Peelable and heat sealable lids for plastic containers are known in the prior art. However, there is still a need to provide plastic container lids having the following combination of properties: a) approximately constant peel strength over a wide range of heat seal temperatures; b) cohesive failure in the heat seal layer upon peeling; and c) high burst strength in the sealed lid.
A principal objective of the present invention is to provide lidstock for making container lids having the above-mentioned combination of constant peel strength, cohesive failure in the heat seal layer and high burst strength.
A related objective of the invention is to provide lidstock material comprising a substrate laminated with a film comprising a mixture of a butene-1 and ethylene copolymer, an ethylene homopolymer or copolymer, an inorganic filler, and optionally, a propylene homopolymer or copolymer.
Additional objectives and advantages of my invention will become apparent to persons skilled in the art from the following detailed description.